Compressor having a piston performing simultaneous functions

ABSTRACT

AN COMPRESSOR HAVING A PISTON PERFORMING SIMULTANEOUS FUNCTIONS, which consists of a piston with a top part having a diameter smaller than that of the bottom part. Over the piston, in a reservoir (which has an outlet for compressed air) over the piston cylinder, is located a valve that covers the whole of the top opening of the cylinder. The bottom reservoir, where a crankshaft is located, is connected to the top part of the piston cylinder through passages that allow air to flow from this bottom chamber into the top part of the cylinder. The bottom reservoir has intake valves that open as the piston moves up and close as the piston moves down.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a COMPRESSOR HAVING A PISTON PERFORMINGSIMULTANEOUS FUNCTIONS, its assembly consisting of a 2-stage compressormechanism, with a piston that performs several simultaneous functionsutilizing each stroke of the piston, so that it performs the functionsof intake and compression at the same time, both in its ascent and inits descent, allowing the prior compression of the air to be compressed.

PRIOR ART AND PROBLEMS TO BE SOLVED

A large number of embodiments and systems are currently known to be usedas compressors using ordinary cylindrical-section pistons, ports, and/orvalves of different types.

The present invention is totally novel in that one flat valve isdirectly used instead of the cylinder head, reducing the total weightand the number of components of the device. This results in the smallersize of the device, and its simplicity reduces the likelihood offailure, and, should any failure occur, repairing and accessing thedifferent components of the devise are easier. Additionally, thecompression ratio is higher due to the fact that the total intake volumeis higher than the volume of the top part of the piston cylinder, wherecompression occurs. It should be borne in mind that the intake surfaceand space (bottom area of the piston) are larger than the compressionsurface and space (top area of the piston, inside the cylinder),especially taking into account that compression, which occurs in thiscompression area, is applied to the previously compressed air from thebottom part of the piston cylinder and the bottom chamber (where thecrankshaft is located). Each stroke of the piston is utilizedefficiently because, as the piston moves up, it closes the ports(passages), compresses the air in the top and bottom parts of thecylinder, draws air from outside into the combustion chamber under thepiston, and, finally, forces the compressed air in the bottom part ofthe cylinder into the bottom chamber and pushes the flat valve, openingthe top opening of the cylinder. As the piston moves down, it allowscompressed air below itself into the top part of the cylinder through avalve in the piston head, further compresses the air below thepiston—thus compressing the air above the piston—, closes the intakevalves in the bottom chamber, draws allows air from outside into thebottom part of the cylinder (opening the corresponding valves bycreating a vacuum effect in this part), and, finally, forces morecompressed air through the ports into the top part of the cylinder.

Considering all the foregoing, this invention is important.

SUMMARY OF THE INVENTION

This invention, titled COMPRESSOR HAVING A PISTON PERFORMINGSIMULTANEOUS FUNCTIONS, relates to an assembly consisting of: amechanism with a piston having an inverted T-shaped longitudinalsection, since the diameter of its bottom part is larger than that ofthe top part. Each part has its corresponding rings and oil scraperrings, which are conventional, widely known, and in the public domain.This piston has the same characteristics as a conventional piston,except for its shape as described above, and is moved through aconnecting rod by the rotation of a crankshaft (which is located in abottom chamber—usually called “crankcase”—located directly under thepiston cylinder). This crankshaft imparts an up-and-down motion to thepiston inside the cylinder enclosing the piston, which enables thepiston to move freely inside the cylinder from top to bottom. Thispiston cylinder has all the conventional characteristics of anycylinder, except for its shape, which fits that of the piston. Thecomplete movement of a piston from one end to the other of the cylinderis called “stroke” or “piston travel.” With each rotation of thecrankshaft, the piston has completed two strokes, one up and one down.Considering that a cycle is a series of occurrences that repeats or isrepeated in one and the same order, this is a compressor with atwo-stroke cycle. It should be taken into account that all thecomponents mentioned herein (piston, cylinder, crankshaft, connectingrod, and crankcase) are widely known and used, both in pistoncompressors and in engines; therefore, no description is necessary.

As mentioned above, unlike other pistons, the diameter of the top partof the piston in this compressor is smaller than that of the bottom partof the piston; the length of each part will depend on the expectedperformance of the compressor, according to the reasonable ratiosallowed by the interrelation of the components and their possibledimensions. Therefore, the diameter of the bottom part of the cylinder,in which the piston is housed and slides, is also larger than that ofthe top part of the cylinder, the length of each part of the cylinderdepending on the length of each part of the piston. Over the piston andin a top chamber, which is directly over the piston cylinder, is locateda flat valve that covers the whole of the top opening of the cylinderand rests on the top outer edge of the piston cylinder, thus acting as acylinder head. (It should be taken into account that the cylindersurfaces as well as the bottom surface of the abovementioned valve andthat of the piston skirt are mirror-polished.) The flat valve stem,which moves up and down, slides in a guide, which keeps it from slidingother than lengthwise. There is a gap in the middle part of the valvestem guide that house spring pushing the flat valve down. This spring isenclosed in a gap or chamber, and actuated by a retainer attached to theflat valve stem at some distance from the bottom end of the stem, thusallowing the proper operation of the spring, forcing the valve down andclosing the top opening of the piston cylinder. The force of the springis to be selected according to the expected initial flat-valve openingpressure because this pressure has to withstand the strength of thespring. When the spring is in operation, the pressure required to openthe flat valve will depend on the pressure existing in the top chamber.The bottom chamber, which houses the crankshaft, and the top part of thepiston cylinder are connected by one or more passages, or ports, whichallow air to flow freely, from the bottom chamber into the top part ofthe cylinder. Two semicircular flat metal valves are attached to thehorizontal flat surface of the piston cylinder, which connects thebottom part of the cylinder, having a larger diameter, to the top partof the cylinder, having a smaller diameter. These valves are attached byone end only; this allows the free movement of the other end, which isthe one that acts as a valve by allowing or preventing the passage ofoutside air, depending on the difference between the pressures existingin the both ends of the each side (top and bottom) of the valves. (Thistype of valve is widely known and used in some compressors and engines.)Two rectangular valves, operating in a fashion similar to that of theabovementioned valves, are located on the top flat surface of the bottomchamber, where the crankshaft is located. These rectangular valves willeither allow or not allow the entrance of outside air.

The bottom of the top part of the piston has two rectangular recesses.These recesses are parallel to the longitudinal axis of the piston andopposite each other. Thus when the piston reaches the top dead center,the recesses will face the inlets, which are located in the top part ofthe piston cylinder, of the passages, or ports, which connect the toppart of the piston cylinder to the bottom chamber, where the crankshaftis located. This causes the air compressed by the travel of the bottompart of the piston to flow through the recesses to the passages and intothe bottom chamber. Therefore, when the piston is at that point, andbecause of their rectangular shape and curved bottoms, the recessesconnect the inlet of the passages to the chamber in which the bottompart of the piston compresses the air previously allowed through theabovementioned semicircular valves. On the piston head is attached acircular valve that forms part of the top surface of the piston. Thisvalve is actuated by pressure difference because, as the piston movesup, the pressure in the top part of the cylinder pushes the valve down,thus causing the valve to tightly seal the top surface of the piston,whereas, as the piston moves down, it creates a vacuum in the top partof the cylinder; this, combined with the pressure of the air below thepiston, causes the valve to open, allowing the air from the bottom partof the cylinder into the top part of the cylinder, thus preventing thevacuum created above the piston from applying an opposite force to thepiston movement.

The whole assembly operates as follows: The force of the crankshaft(which is moved by a motor) acting on the connecting rod causes thepiston to move down, closing the top opening in the piston cylinder viathe flat valve, and initially creating a vacuum effect in the top partof the cylinder. This, combined with the downward piston movementcompressing the air below the piston—with such compression closing thevalves that allow outside air into the bottom chamber—, increases thepressure in the bottom part of the cylinder, causing the valve at thecenter of the surface of the piston to open, allowing air into the toppart of the cylinder and preventing a vacuum effect that would apply anopposite force to the downward piston movement thus preventing a strainon the crankshaft motor and increasing the subsequent compression in thetop part of the cylinder.) This valve remains open until the pressure inthe top part of the cylinder is higher than that in the bottom part ofthe cylinder. The downward piston movement creates a vacuum effect inthe bottom part of the cylinder (above the bottom part of the piston),causing the immediate opening of the semicircular intake valves, thusdrawing air in from outside. During downward piston movement—almost atthe end of the piston travel—, the piston opens the outlets of thepassages that connect the top part of the cylinder to the bottomchamber, and some air compressed below the piston flows into the toppart of the cylinder, thus balancing the pressure between both ends ofthe passage, which will be higher than atmospheric pressure.

Afterwards, as the piston begins to move down, it closes the outlets ofthe passages that connect the top part of the cylinder to the bottomchamber. Due to pressure difference, this causes the intake valves ofthe bottom chamber to open, drawing air in from outside, while thepiston compresses the air that entered the bottom part of the cylinderduring the downward stroke of the piston, closing the intake valves ofthis part by pressure. The piston compresses the previously compressedair located in the top part of the cylinder, tightly closes the valvethat is at the top of the piston and that forms part of its top surface.As mentioned above, during its upward stroke, the piston compresses theair located in the top part of the cylinder until, as the piston is verynear the flat valve that closes the top opening of the cylinder, thepressure causes the valve to open. As the piston moves further up andthe flat valve begins to move down, due to the exhaust of the compressedair between them, a shock-absorbing effect (like a deflating aircushion) is created which allows both components (piston and valve) tomake gentle contact with each other, they becoming such an integralassembly that no significant amount of air will remain between them. Asthe flat valve makes contact with the piston, the top ends of bothrectangular recesses in the skirt of the top part of the piston willface the outlet of the passages that connect the top part of thecylinder to the bottom chamber, while the bottom ends of the recesseswill continue to face the bottom part of the cylinder; therefore, theserecesses act as passages that allow the air compressed in the bottompart of the cylinder into the bottom chamber, and, thus, stop applyingan opposite force to the upward piston movement and push the piston fromthe bottom chamber due to an increase in the air pressure, which closesthe intake valves of the bottom chamber.

The arrangement and flat shape of the top valve allow it to expand (dueto the temperature reached in the compression stroke) and with no riskof the valve getting caught.

The compressed air released through the openings in the flat valve exitsthe top chamber through a passage in the chamber into, for example, anair receiver. Afterwards, the piston begins to move down and, therefore,the cycle starts again. Both the cooling, air-filter, and lubricationsystem and the intake-valve system of this assembly are conventionallyused in compressors, and, as their operation is in the public domain, nodescription is necessary herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Several schematic drawings of a preferred embodiment of the invention,which should be taken as an example without limitation, are annexedhereto so that the invention may be better understood, where:

FIG. 1 is a view in longitudinal section parallel to the axis of thecrankshaft, showing the piston at a specific point on its travel.

FIG. 2 is a view in longitudinal section perpendicular to the axis ofthe crankshaft, showing the piston at a specific point on its travel.

FIG. 3 is a view showing the details of the flat valve retainer thatserves as a stop for the spring pushing the valve down.

FIG. 4 is a view showing the closed arrangement of the valve operatingin the top part of the piston.

FIG. 5 is a view showing the open arrangement of the valve operating inthe top part of the piston.

FIG. 6 is a perspective view of the semicircular valves in the bottompart of the piston, detached form the cylinder.

FIG. 7 is a bottom view of the arrangement of the semicircular valves inthe bottom part of the piston.

FIGS. 8-15 are views in longitudinal section parallel to the axis of thecrankshaft and longitudinal section perpendicular to the axis of thecrankshaft, showing the piston at specific points on its travel, simplyto better describe the operation of the assembly, where:

FIGS. 8 and 9 are views in longitudinal section parallel to the axis ofthe crankshaft and longitudinal section perpendicular to the axis of thecrankshaft, respectively, showing the piston at a specific point on itstravel, which will be taken as the initial point of the piston stroke,simply to better describe the operation of the assembly.

FIGS. 10 and 11 are views in longitudinal section parallel to the axisof the crankshaft and longitudinal section perpendicular to the axis ofthe crankshaft, respectively, showing the piston at a subsequent point,with respect to the above figures, on its travel.

FIGS. 12 and 13 are views in longitudinal section parallel to the axisof the crankshaft and longitudinal section perpendicular to the axis ofthe crankshaft, respectively, showing the piston at a subsequent point,with respect to the above figures, on its travel.

FIGS. 14 and 15 are views in longitudinal section parallel to the axisof the crankshaft and longitudinal section perpendicular to the axis ofthe crankshaft, respectively, showing the piston at a subsequent point,with respect to the above figures, on its travel.

DETAILED DESCRIPTION OF THE INVENTION

In order for the present invention to be clearly understood and the mainidea of the invention to be easily implemented, a precise description ofa preferred embodiment of the invention is provided below by referenceto the schematic drawings annexed hereto, with all reference numbersindicating the same or corresponding items, all of which to be taken asan example without limitation, where:

FIGS. 1 and 2 are views in longitudinal section parallel to the axis ofthe crankshaft and longitudinal section perpendicular to the axis of thecrankshaft, respectively, showing the piston at one and the same pointon its travel, simply to better describe the components of the assembly.These figures show that the mechanism assembly consists of a piston (1)having a top part (1A) with a smaller diameter than that of the bottompart (1B), so the piston has an inverted T-shaped longitudinal section.Therefore, the diameter of the bottom side of the piston is larger thanthat of the top side. The piston moved by the rotation of a crankshaft(2), which is located in a bottom chamber (3). This bottom chamber islocated directly under the piston cylinder (4). The crankshaft moves aconnecting rod (5), so that the crankshaft, combined with the connectingrod (5), imparts an up-and-down motion to the piston (1)—this mechanismfor moving the piston is conventional; therefore, it is in the publicdomain. As mentioned above, unlike other pistons, the diameter of thetop part (1A) of the piston in this device is smaller than that of thebottom part (1B) of the piston; therefore, the diameter of the top part(1A) of the piston cylinder (4), or chamber in which the piston ishoused and slides, is also smaller than that of the bottom part (1B) ofthe cylinder, the length of each part of the cylinder depending on thelength of each part of the piston (1).

Over the piston (1) and in a top chamber (6), which is also directlyover the piston cylinder (4A), is located a flat valve (7) that coversthe whole of the opening in the top part of the cylinder (4A), thusacting as a movable cylinder head. The stem (7A) of the flat valve (7),which moves up and down, slides in two guides (8 and 8A), which keep itfrom sliding other than lengthwise. There is a spring (9) between theguides that pushes the flat valve (7) down. This spring is enclosed in achamber (10), and applies pressure down on a retainer (11) attached tothe flat valve stem (7A), at some distance from the top end of the flatvalve, thus allowing the proper operation and actuation of the spring(9) in conjunction with the flat valve (7), causing the valve to closethe top outlet of the top part of the piston cylinder (4A).

The bottom reservoir (3), where the crankshaft (2) is located, isconnected to the top part of the cylinder (4A) through one or twopassages (12 and 12A) that allow air to flow freely, from this bottomchamber (3) into the top part of the cylinder (4A), as long as the toppart of the piston (1A) does not block the outlets (12B and 12C) locatedin the top part of the cylinder (4A).

There are two air inlets (13 and 13A) in the bottom reservoir (3), wherethe crankshaft (2) is located. These inlets are adjusted by valves (14and 14A) that allow the entrance of outside air through passages (18 and18A) as the piston (1) begins to move up creating a vacuum effect, whichreduces the pressure in the bottom chamber, so that the outsideatmospheric pressure will be higher, causing these valves to open due topressure difference. These valves open when the piston reaches the topdead center, because the pressure in the bottom chamber increases due tothe fact that, as both recesses (19 and 19A) in the piston skirt (at thebottom of the top part of the piston) are opposite each other, thecompressed air located in the bottom part of the cylinder flows into thebottom chamber, as described above. And there is an outlet (15) in thetop reservoir (6) to, for example, an air receiver.

There is a valve (16) that forms part of the top surface of the piston.This valve (shown in its open position) tightly closes a centralcircular opening when the pressure above the valve is higher than thepressure below the valve; in the opposite case, the valve will open. Thevalve will close due to a spring that acts on a retainer located at theend of the valve stem. When the valve opens, the air located in thebottom chamber will flow through the piston and the valve-openingpassage into the chamber in the top part of the piston cylinder.

Two semicircular flat metal valves (17 and 17A) are attached to thehorizontal flat surface of the piston cylinder, which connects thebottom part of the cylinder, having a larger diameter, to the top partof the cylinder, having a smaller diameter. These valves are attached byone end only; this allows the free movement of the other end, which isthe one that acts as a valve.

Both the bottom and top parts of the piston have each theircorresponding rings and oil-scraper rings (20 and 21A), which areconventional rings and allow the proper operation of the pistonpreventing it from getting caught.

FIG. 3 is a magnified view of the joint between the retainer (I 1) andthe “valve sprig retainer lock” (11A), a part of the flat valve stem(7A), and the spring (9). This conventional thrust system is the same asthe one used by the piston-head valve. FIGS. 4 and 5 are magnified viewsin longitudinal section through the middle of the piston, showing thepiston—head valve in the closed (FIG. 4) and open (FIG. 5) positions.These figures clearly show the valve (16), the valve stem (16A), thespring (21) pushing the valve (16) down, and the area of the piston head(4A) that includes the valve (16).

FIG. 5 shows the air flow, represented by flow direction arrows, withthe valve (16) in the open position.

FIG. 6 is a bottom perspective view of the semicircular valves (17 and17A) in the bottom part of the piston, detached from the cylinder,showing the holes for setscrews (22, 22A, 22B, and 22C).

FIG. 7 is a bottom plan view in cross section through the bottom part ofthe piston cylinder (4B), showing the arrangement of the semicircularvalves (17 and 17A), which are located in the bottom part of thecylinder. This figure shows the air intake passages (18 and 18A) at theends of and behind the valves, as well as the holes for setscrews (22,22A, 22B, and 22C), the bottom part of the cylinder (4B), and the toppart of the cylinder (4A).

FIGS. 8-15 are views in longitudinal section parallel to the axis of thecrankshaft and longitudinal section perpendicular to the axis of thecrankshaft, showing the piston at specific points on its travel, simplyto better describe the operation of the assembly. These figures onlylist again those components required for a simpler interpretation of thefigures. The operation of the assembly is as follows:

FIGS. 8 and 9 show the piston at a specific point on its travel, whichwill be taken as the initial point of the piston stroke. The force ofthe crankshaft (which can moved by any motor with the required power)acting on the connecting rod causes the piston to move down, closing thetop opening in the piston cylinder via the flat valve (7), and initiallycreating a vacuum effect in the top part of the cylinder (4A). This,combined with the downward piston movement compressing the air below thepiston—with such compression closing the valves (14 and 14A) that allowair from outside through the passages (13 and 13A) into the bottomchamber—, increases the pressure in the bottom part of the cylinder,causing the valve (16) at the center of the piston top surface to open,allowing air into the top part of the cylinder (4A), which prevents avacuum effect that would apply an opposite force to the downward pistonmovement (thus preventing a strain on the crankshaft motor andsubsequently increasing the compression in the top part of thecylinder.) This valve (16) remains open until the pressure in the toppart of the cylinder is higher than that in the bottom part of thecylinder. The downward piston movement creates a vacuum effect in thechamber in bottom part of the cylinder (4B) (above the bottom part (1B)of the piston), causing the immediate opening of the semicircular valves(17 and 17A), and drawing air in from outside through the passages (18and 18A). During downward piston movement—almost at the end of thepiston travel (see FIGS. 10 and 11)—, the piston opens the outlets ofthe passages (12B and 12C) that connect the top part of the cylinder tothe bottom chamber, and some air compressed below the piston flows intothe top part of the cylinder (4A), thus balancing the pressure betweenboth ends of the passage, which will be higher than atmosphericpressure.

As the piston begins to move down (see FIGS. 12 and 13), it closes theoutlets of the passages that connect the top part of the cylinder to thebottom chamber. Due to pressure difference, this causes the intakevalves (14 and 14A) of the bottom chamber to open, drawing air in fromoutside, while the piston compresses the air that entered the bottompart of the cylinder (4B), closing the intake valves of this part bypressure. The piston compresses the previously compressed air located inthe top part of the cylinder, tightly closes the valve that is at thetop of the piston (piston head) and that forms part of its top surface.As mentioned above, during its upward stroke, the piston compresses theair located in the top part of the cylinder until (see FIGS. 14 and 15),as the piston is very near the flat valve that closes the top opening ofthe cylinder, the pressure causes the valve to open. As the piston movesfurther up and the flat valve begins to move down, due to the exhaust ofthe air between them, an air shock-absorbing effect is created whichallows both components (piston and flat valve) to make gentle contactwith each other, to the extent that no significant amount of air willremain between them. As the flat valve makes contact with the piston,the top ends of both rectangular recesses (19 and 19A) in the skirt ofthe top part of the piston will face the outlet of the passages thatconnect the top part of the cylinder to the bottom chamber, while thebottom ends of the recesses will continue to face the bottom part of thecylinder; therefore, these recesses act as passages that allow the aircompressed in the bottom part of the cylinder into the bottom chamber,and, thus, stop applying an opposite force to the upward piston movementand push the piston from the bottom chamber due to an increase in theair pressure, which closes the intake valves of the bottom chamber.

The arrangement and flat shape of the top valve allow it to expand (dueto the temperature reached in the compression stroke) and with no riskof the valve getting caught.

The compressed air released through the openings in the flat valve exitsthe top chamber through a passage in the chamber for such purpose.

Afterwards, the piston begins to move down and, therefore, the cyclestarts again. Both the cooling, air-filter, and lubrication system andthe intake-valve system of this assembly are conventionally used incompressors, and, as their operation is in the public domain, nodescription is necessary herein.

This invention may reasonably be implemented incorporating modificationsto its construction, materials, and form, as long as this is donewithout departure from the fundamental principles clearly specified inthe following claims:

1. (canceled)
 2. A compressor, comprising: a piston cylinder; aninverted T-shaped piston at least partially disposed in said pistoncylinder, wherein said piston has a top part with a top surface and abottom part with a bottom surface, wherein said top part is forward ofsaid bottom part during an up stroke of said piston, and wherein saidbottom part is forward of said top part during a down stroke of saidpiston, wherein said bottom surface has a larger area than said topsurface, wherein said piston cylinder and said piston at least partiallydefine a top part of cylinder and a bottom part of cylinder at least atone point during travel of said piston, wherein said bottom surface ofsaid bottom part at least partially defines a bottom chamber; and avalve carried by said piston and having an open position to allow air toflow therethrough, wherein said valve has a closed position to preventair from flowing therethrough, and wherein in said closed position ofsaid valve an upper surface of said valve aligns with said top surfaceof said top part of said piston to form a flat surface.
 3. Thecompressor as set forth in claim 2, further comprising a flat valve,wherein said flat valve and said top surface of said top part of saidpiston at least partially define said top part of cylinder when spacedfrom one another, and wherein said flat valve and said flat surfaceformed during alignment of said valve with said top surface of said toppart of said piston contact one another at least at one point duringtravel of said piston.
 4. The compressor as set forth in claim 3,wherein at least at some point during an up stroke of said piston airpressure in said top part of cylinder increases in order to open saidflat valve to subsequently cause air in said top part of cylinder to bereleased across said flat valve and out of an outlet, and whereinsubsequent to releasing air from said top part of cylinder across saidflat valve and out of said outlet said flat valve and said flat surfaceformed during alignment of said valve with said top surface of said toppart of said piston contact one another.
 5. The compressor as set forthin claim 2, wherein at least at some point during a down stroke of saidpiston said bottom surface of said bottom part of said piston compressesair in said bottom chamber, and further comprising a bottom part ofcylinder valve that is open at least at some point during a down strokeof said piston to allow air to enter said bottom part of cylinder. 6.The compressor as set forth in claim 2, wherein said valve is in saidopen position at least at some point during a down stroke of said pistonto allow air in said bottom chamber to flow through said piston and outof said valve and into said top part of cylinder.
 7. The compressor asset forth in claim 2, wherein at least one passage external to saidpiston is present between said bottom chamber and said top part ofcylinder, and wherein said top part of said piston blocks an opening ofsaid passage to prevent air from traveling therethrough at least at somepoint during a down stroke of said piston, and wherein said top part ofsaid piston clears said opening of said passage to allow air flow fromsaid bottom chamber to said top part of cylinder at least at some pointduring a down stroke of said piston.
 8. The compressor as set forth inclaim 2, wherein at least at some point during an up stroke of saidpiston air is compressed in said top part of cylinder and in said bottompart of cylinder by said piston, and further comprising a bottom chambervalve that is open at least at some point during an up stroke of saidpiston to allow air to enter said bottom chamber.
 9. The compressor asset forth in claim 2, wherein said piston defines at least onerectangular recess, and wherein at least at some point during the travelof said piston air is transferred from said bottom part of cylinderthrough said rectangular recess and through a passageway external tosaid piston into said bottom chamber.
 10. A compressor, comprising: apiston cylinder; an inverted T-shaped piston at least partially disposedin said piston cylinder, wherein said piston has a top part and a bottompart, wherein said top part is forward of said bottom part during an upstroke of said piston, and wherein said bottom part is forward of saidtop part during a down stroke of said piston, wherein said pistoncylinder and said piston at least partially define a top part ofcylinder and a bottom part of cylinder at least at one point duringtravel of said piston, wherein said bottom part at least partiallydefines a bottom chamber; a valve carried by said piston and having anopen position to allow air to flow therethrough, wherein said valve hasa closed position to prevent air from flowing therethrough; and apassage that allows fluid communication between said bottom chamber andsaid top part of cylinder at least at one point during travel of saidpiston, and wherein said passage allows fluid communication between saidbottom chamber and said bottom part of cylinder at least at one pointduring travel of said piston.
 11. The compressor as set forth in claim10, further comprising a flat valve, wherein in the closed position ofsaid valve a flat surface is formed on the top of said top part of saidpiston, wherein said flat valve and said flat surface contact oneanother at least at one point during travel of said piston.
 12. Thecompressor as set forth in claim 11, wherein at least at some pointduring an up stroke of said piston air pressure in said top part ofcylinder increases in order to open said flat valve to subsequentlycause air in said top part of cylinder to be released across said flatvalve and out of an outlet, and wherein subsequent to releasing air fromsaid top part of cylinder across said flat valve and out of said outletsaid flat valve and said flat surface of said top part of said pistoncontact one another, wherein a surface of said flat valve and said flatsurface of said top part of said piston are mirror-polished.
 13. Thecompressor as set forth in claim 10, wherein at least at some pointduring a down stroke of said piston said bottom part of said pistoncompresses air in said bottom chamber, and further comprising a bottompart of cylinder valve that is open at least at some point during a downstroke of said piston to allow air to enter said bottom part ofcylinder.
 14. The compressor as set forth in claim 13, wherein saidbottom part of cylinder valve is a semi-circular flat metal valve. 15.The compressor as set forth in claim 10, wherein said valve is in saidopen position at least at some point during a down stroke of said pistonto allow air in said bottom chamber to flow through said piston and outof said valve and into said top part of cylinder.
 16. The compressor asset forth in claim 10, wherein said top part of said piston blocks anopening of said passage to prevent air from traveling therethrough atleast at some point during a down stroke of said piston, and whereinsaid top part of said piston clears said opening of said passage toallow air flow from said bottom chamber to said top part of cylinder atleast at some point during a down stroke of said piston.
 17. Thecompressor as set forth in claim 10, wherein at least at some pointduring an up stroke of said piston air is compressed in said top part ofcylinder and in said bottom part of cylinder by said piston, and furthercomprising a bottom chamber valve that is open at least at some pointduring an up stroke of said piston to allow air to enter said bottomchamber.
 18. The compressor as set forth in claim 10, wherein saidpiston defines at least one rectangular recess having curved ends, andwherein at least at some point during the travel of said piston air istransferred from said bottom part of cylinder through said rectangularrecess through said passageway and into said bottom chamber.
 19. Thecompressor as set forth in claim 18, wherein said point during thetravel of said piston in which air is transferred from said bottom partof cylinder through said rectangular recess through said passageway andinto said bottom chamber occurs during the top dead center position ofsaid piston.
 20. The compressor as set forth in claim 10, wherein saidbottom part of said piston has a larger diameter than said top part ofsaid piston.
 21. A compressor, comprising: a piston cylinder; aninverted T-shaped piston at least partially disposed in said pistoncylinder, wherein said piston has a top part and a bottom part, whereinsaid top part is forward of said bottom part during an up stroke of saidpiston, and wherein said bottom part is forward of said top part duringa down stroke of said piston, wherein said piston cylinder and saidpiston at least partially define a top part of cylinder and a bottompart of cylinder at least at one point during travel of said piston,wherein said bottom part at least partially defines a bottom chamber; avalve carried by said piston and having an open position to allow air toflow therethrough, wherein said valve has a closed position to preventair from flowing therethrough; a passage that allows fluid communicationbetween said bottom chamber and said top part of cylinder at least atone point during travel of said piston, and wherein said passage allowsfluid communication between said bottom chamber and said bottom part ofcylinder at least at one point during travel of said piston; a flatvalve, wherein in the closed position of said valve a flat surface isformed on the top of said top part of said piston, wherein said flatvalve and said flat surface contact one another at least at one pointduring travel of said piston; and a bottom part of cylinder valve thatis open at least at some point during a down stroke of said piston toallow air to enter said bottom part of cylinder; wherein said top partof said piston clears an opening of said passage to allow air flow fromsaid bottom chamber to said top part of cylinder at least at some pointduring a down stroke of said piston; wherein said piston defines atleast one rectangular recess having curved ends, and wherein at a topdead center position of said piston air is transferred from said bottompart of cylinder through said rectangular recess through said passagewayand into said bottom chamber.